A320 Nws

[Thunderbug]

A320 series.

Does the Park Brake have any effect on the NWS?

i.e. If you set the brake to park, does it isolate and prevent movement of the NWS?

Also some later built models have the NWS on the Yellow system rather than Green - does this have any impact in the above condition?


Thanks in advance - trying to resolve a friendly discussion for which the manuals seem poorly resourced.

T'Bug :ok:

[Microburst2002]

1- The brake system and the NWS are independent of each other. Each has its own hydraulic selector valves, no matter which hydraulic system supplies the NWS.
2- The BSCU does not use brake system information for the control of the NWS.
3- BUT: aside from the computer, you need hidraulic power.

On the ground with one engine running (and the towing lever of the electrical box in normal) the BSCU allows you to turn the nose wheel.... Provided it is hydraulicaly powered. Here we can find what you are looking for:

In the older version (with green hydraulic for NWS) if you have engine number two running, the PTU will power the green hydraulic only when the towing lever is in normal and the parking brake is released. I think that this condition is though for the case of a power push towing.

In the yellow hydraulic supplied NWS A320s, I guess you can move the nose wheel with the park brake set because you don't need the PTU.

Hope it helped